Department of Mechanical Engineering, University of Minnesota, 111, Church Street, SE, Minneapolis, MN 55455, USA.
Department of Microbiology and Immunology, University of Minnesota, Microbiology Research Facility, 689, SE, 23rd Ave, Minneapolis, MN 55455, USA.
Free Radic Biol Med. 2018 Aug 20;124:275-287. doi: 10.1016/j.freeradbiomed.2018.05.083. Epub 2018 Jun 2.
Different chemical pathways leading to the inactivation of Pseudomonas aeruginosa and Staphylococcus aureus by a cold atmospheric pressure plasma jet (APPJ) in buffered and non-buffered solutions are reported. As APPJs produce a complex mixture of reactive species in solution, a comprehensive set of diagnostics were used to assess the liquid phase chemistry. This includes absorption and electron paramagnetic resonance spectroscopy in addition to a scavenger study to assess the relative importance of the various plasma produced species involved in the inactivation of bacteria. Different modes of inactivation of bacteria were found for the same plasma source depending on the solution and the plasma feed gas. The inactivation of bacteria in saline is due to the production of short-lived species in the case of argon plasma when the plasma touches the liquid. Long-lived species (ClO) formed by the abundant amount of O radicals produced by the plasmas played a dominant role in the case of Ar + 1% O and Ar + 1% air plasmas when the plasma is not in direct contact with the liquid. Inactivation of bacteria in distilled water was found to be due to the generation of short-lived species: O &O for Ar + 1% O plasma and O (and OH in absence of saline) for Ar plasma.
报道了冷大气压等离子体射流（APPJ）在缓冲和非缓冲溶液中使铜绿假单胞菌和金黄色葡萄球菌失活的不同化学途径。由于 APPJ 在溶液中产生复杂的反应物种混合物，因此使用了一整套诊断方法来评估液相化学。这包括吸收和电子顺磁共振波谱学，以及清除剂研究，以评估参与细菌灭活的各种等离子体产生的物质的相对重要性。对于相同的等离子体源，根据溶液和等离子体进料气体的不同，发现了不同的细菌灭活模式。在等离子体接触液体的情况下，当等离子体为氩气时，盐水中细菌的失活是由于短寿命物种的产生。当等离子体未与液体直接接触时，由等离子体产生的大量 O 自由基形成的长寿命物种（ClO）在 Ar + 1%O 和 Ar + 1%空气等离子体的情况下起主要作用。在蒸馏水，细菌的失活被发现是由于短寿命物种的产生：O 和 O 对于 Ar + 1%O 等离子体，以及 O（在没有盐水的情况下为 OH）对于 Ar 等离子体。
